From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0F05D3C76BD for ; Wed, 17 Jun 2026 13:18:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781702308; cv=none; b=s+IoWcj1dPNth+qq6sUHzK7duVBN5uu3oL1sZr+BHBbpkqznhD9XhaG2SdqbV7cxxck2qu6FmvciiHI9VtosNWlurPgxzh7wOrTxiIBW1DbQQ6vyg3Dt2AD4BUdWiY2626inu4O8GnwMP+uPCwJ4NzIM7kLoVd8k3jGcPzR7s4M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781702308; c=relaxed/simple; bh=MCeh1YzlrMSIpzgMuJWvusd/9tGfEb3VP3Iy+aO/AVI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=J4TtNwPVLFXK4b6ZX4CnIzTTMiR+I1bAkAK387tvjXpHtelZplIixNt/hqceGqXasC3TUuWzEvj6j3IeBUqeQICO9haG6217ADZr2qeShKFn9FAO51x+kU9WXZII60o/Pr1H1j6Y55EoXk0csv4YpMW8FPh50a/i6yP5+0q3W7k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=cs5hlXGr; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="cs5hlXGr" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1781702306; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=VsqXFSMNs8zrw+jri9zTq847xOPB6KWpHG/yzX/wDzo=; b=cs5hlXGrS8uh8tgvVN1AvVyYy243AIyYBwcsNPvWQehWhUEbIIjltQKCCDs4JW+OpQ8gZy QnRiIjo9TSQPupD2f0BjQiHJuMx8ldZKXB1ugejTx82PRpWLyIzo2WU2EUmkWvLVH2Hri7 cmk58We54H5eSlTdV3GokNrAeewLIiw= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-493-60FLF4XzP5GKECGcO-qTPw-1; Wed, 17 Jun 2026 09:18:23 -0400 X-MC-Unique: 60FLF4XzP5GKECGcO-qTPw-1 X-Mimecast-MFC-AGG-ID: 60FLF4XzP5GKECGcO-qTPw_1781702301 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9218B1954B07; Wed, 17 Jun 2026 13:18:21 +0000 (UTC) Received: from vschneid-thinkpadt14sgen2i.remote.csb (unknown [10.44.34.165]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D188F180049F; Wed, 17 Jun 2026 13:18:17 +0000 (UTC) From: Valentin Schneider To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Tomas Glozar , Costa Shulyupin , Crystal Wood , John Kacur , Ivan Pravdin , Jonathan Corbet Subject: [RFC PATCH v2 0/4] tracing/osnoise: Track IPIs Date: Wed, 17 Jun 2026 15:17:55 +0200 Message-ID: <20260617131803.2988989-1-vschneid@redhat.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 X-Mimecast-MFC-PROC-ID: _eF_DtmGCTnTGihLnua7qNIWHHv5LbELY7EK9mc4hvc_1781702301 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi folks, So I've seen a few times now reports of latency spikes caused by IPIs, usually because of isolation misconfiguration, but only detected at the tail of end e.g. a 24h timerlat run. It's not because those IPIs are rare, but rather that they don't by themselves cause a monitered CPU to reach the latency threshold, it's usually a combined interference that gets us there. I'd like to make it easier to detect such misconfigurations and thus IPIs hitting supposedly-isolated CPUs. I initially kludged a timerlat option to stop tracing as soon as an IPI was sent to a monitored CPU, regardless of the latency threshold. It sort of did the trick, but Tomáš convinced me timerlat wasn't really the place for that. So here's IPI tracking added to osnoise. This time around fully in userspace, as Tomáš pointed out to me that this will make it a lot easier to deploy to older kernels. Based on top of linux/next at 'next-20260616' to have the latest libsubcmd changes. Cheers, Valentin Revisions ========= v1 -> v2 ++++++++ o Dropped the in-kernel osnoise_sample changes and made it all userspace Valentin Schneider (4): rtla/osnoise: Add IPI tracking cmdline option rtla/osnoise: Record IPI count in osnoise top rtla/osnoise: Trace IPI events when recording a trace file rtla/osnoise: Leverage IPI event filters when tracing a subset of CPUs Documentation/tools/rtla/rtla-osnoise-top.rst | 4 + tools/tracing/rtla/src/cli.c | 1 + tools/tracing/rtla/src/cli_p.h | 3 + tools/tracing/rtla/src/common.c | 2 +- tools/tracing/rtla/src/common.h | 3 +- tools/tracing/rtla/src/osnoise.c | 17 +- tools/tracing/rtla/src/osnoise_top.c | 153 +++++++++++++++++- 7 files changed, 179 insertions(+), 4 deletions(-) -- 2.54.0